Mobile terminals, such as User Equipment (UE), are allocated Scheduling Request (SR) resources on a Physical Uplink Control Channel (PUCCH) to be able to inform a base station, such as e.g. an eNodeB, that the UE has data to be sent. Thus, the UE will submit an SR in a slot or resource of the PUCCH, and a scheduler of the eNodeB will subsequently attend to the SR and schedule the UE accordingly for data transmission.
The SR resources on the PUCCH can be allocated using different strategies. There are four different ways to assign the allocations to the PUCCH:                1. In time domain: allocating different UEs to different Transmission Time Intervals (TTIs),        2. In frequency domain: use different Resource Blocks (RBs) for different UEs,        3. Different cyclic shifts: users can use the same RBs and the same TTI but be separated in cyclic shifts, and        4. Different orthogonal sequences: users with the same RB, same TTI, and same cyclic shift can use different orthogonal sequences to be separated from each other.        
In Long-Term Evolution (LTE) wireless communication networks, orthogonal frequency-division multiplexing (OFDM) modulation is employed, and the scheduler of the eNodeB dynamically assigns OFDM resource blocks to UEs for uplink or downlink transmission. These resource blocks assignments consists of both time and frequency assignments.
With reference to FIG. 1, the smallest physical resource in LTE is called a resource element and consists of one OFDM subcarrier over the duration of one OFDM symbol. An RB consists of 12 OFDM subcarriers over a 0.5 ms slot. The allocation of RBs is defined over Transmission Time Intervals (TTIs) of 1 ms and therefore the minimum scheduling unit is called an RB pair which consists of two RBs. Any number of RBs, from 1 to 110, can be allocated to a UE. This represents a bandwidth between 0.18 and 19.8 MHz. As previously was mentioned, and as will be discussed in more detail, the allocation of SR resources can further be complemented with the use of cyclic shifts and orthogonal sequences.
Each RB pair on the PUCCH has 12 different cyclic shifts and 3 orthogonal sequences making it possible to allocate 36 SR resources on the same TTI and the same RB if all orthogonal sequences and all cyclic shifts are used. In order not to waste RBs on the PUCCH, it is desirable to make use of all SR resources.
In the art, when using SRs on the PUCCH to request resources for the UEs, it may happen that the scheduler of the eNodeB schedules a UE even though the UE did not submit an SR in an SR resource. Thus, the scheduler falsely detects a signal in the SR resource and considers the UE associated with said SR resource to have made a scheduling request. As a consequence, resources are allocated to users which effectively has not requested such allocation.